code: def test_context_manager(self, mock_close: MagicMock) -> None:
      with bcs.ClientSession() as session:
          assert isinstance(session, bcs.ClientSession)
      assert mock_close.call_count == 1
      assert mock_close.call_args[0] == ("closed",)
      assert mock_close.call_args[1] == {}
  
file_path: bokeh/tests/unit/bokeh/client/test_session__client.py
imports: from __future__ import annotations
  import pytest
  from unittest.mock import MagicMock, patch
  import bokeh.client.session
label_desc: Use image node_id 8 for calling the Test_ClientSession obj's underlying member method code with example usage: obj.test_context_manager(mock_close) without return types